you're gonna have trouble getting anything downloaded on a shaped speed.
You need to connect to the nintendo server, verify who you are, check settings, check firmware, get latest firmware etc... (this is all in the background). If you buy points online then you need to connect to their secure server, verify your details eg: credit card or points card. After that you can then download games. Granted most games are only a couple 100k for nes, but they do get bigger. N64 games can run from 6mb each to 30mb (OOT and MM - not out yet damn it!!!).
I would say that your wii won't be able to do this on the shaped speed of 56k or 64k.
PC's can be altered to allow shaped speeds to work better. There is a great program you can get called TCP Optimizer (Speed guide) for the PC. This allows you to tell your PC that you are shaped to 56k or 64k and the PC reacts to this. Now obviously you cannot run this on the Wii.
There is a global suggestion you can try (but i have not done it). Anyone on a shaped speed should be able to get into their router settings (a descent router that it), and change their MTU (Maximum Transmission Unit) settings. The default is MTU=1500. You should change it to 576.
This may make a difference, but as I said I haven't tried it and I haven't hit shaped speed yet.
:)
26/12/2006
The Big Blue Velour Marble